Incremental value of copeptin to highly sensitive cardiac Troponin I for rapid rule-out of myocardial infarction

Copeptin plus troponin in the rapid rule out of acute myocardial infarction and prognostic value on post-myocardial infarction outcomes: a systematic review and diagnostic accuracy study

BACKGROUND

A critical and unmet therapeutic need is the prompt and reliable exclusion of acute myocardial infarction (AMI), which would allow for prompt discharge from the emergency department. High-sensitivity troponin (HS-TnT) combined with copeptin has been proposed to expedite the diagnostic exclusion of AMI in addition to its predictive usefulness in the intermediate and long-term outcomes of AMI. The European Society of Cardiology recommends the Global Registry of Acute Coronary Events (GRACE) as a prognostic score to manage acute coronary syndrome (ACS) without ST segment elevation. The purpose of this study was to compare the diagnostic accuracy of HS-TnT combined with copeptin in ruling out AMI compared to HS-TnT alone. By combining a low GRACE score (108) with negative HS-TnT (14 ng/L) and copeptin (14 pmol/L), non-ST and ACS were reliably ruled out, including non-ST segment elevation MI and unstable angina.

RESULTS

The present research included nine studies with a total of 13,232 participants. The negative predictive value (NPV) for copeptin and HS-TnT was found to be slightly higher in combination (62-99%) than for HS-TnT alone (60-99%). The sensitivity of copeptin ranged from 0% to 100%, with a pooled sensitivity of 0.79 (CI 95% 0.76, 0.82). The specificity of copeptin ranged from 13% to 100%, with a pooled specificity of 0.89 (CI 95% 0.85, 0.91), a pooled positive likelihood ratio (PLR) of 9.86 (CI 95% 4.42, 22.02), and a pooled negative likelihood ratio (NLR) of 0.08. (95% CI 0.01, 0.44).

CONCLUSIONS

The use of combined negative copeptin and highly sensitive troponin testing in low-to-intermediate risk patients with suspected acute coronary syndrome resulted in a quick discharge with a safe and rapid rule out of non-ST + ACS.

Improving the ACS Triage-Using High Sensitivity TroponinI and Copeptin for Early 'Rule-Out' of AMI

Rule-out of acute myocardial infarction (AMI) in patients presenting with acute chest pain at the emergency department (ED) is a major challenge across the globe. Patients presenting very early with chest pain may provide a diagnostic challenge even when using a cardiac necrosis specific biomarker, high sensitivity troponin (hs-Tn) as they are elevated at 3-6 h after the symptom onset. Copeptin is a marker of acute hemodynamic stress which is released within few minutes of the occurrence of MI and is elevated immediately at the presentation of patients with AMI. This indicates a complementary pathophysiology and kinetics of these two biomarkers. Hence, we evaluated whether or not a protocol with combined testing of copeptin and hs-TnI at admission in patients presenting with chest pain within 6 h in low to intermediate risk and suspected ACS leads to an earlier diagnosis of AMI and thereby, aids to prevent a higher proportion of major adverse cardiac events than the current standard protocol followed in ED. A total of 148 patients as per the inclusion criterion were recruited for the study. The dual biomarker copeptin and hs-TnI allows a rule-out of AMI at presentation with a sensitivity of 100% and NPV of 99.8%. Hence, the use of dual biomarker in conjunction with clinical assessment may obviate the need for a prolonged stay in the ED and retesting hs-TnI after 2 h (for delta check) in more than two-thirds of the patients. The inclusion of these tests could have an impact on the economic burden of the ED without jeopardizing the outcome for the patient.

High-sensitivity troponin I with or without ultra-sensitive copeptin for the instant rule-out of acute myocardial infarction

Background

The instant, single-sampling rule-out of acute myocardial infarction (AMI) is still an unmet clinical need. We aimed at testing and comparing diagnostic performance and prognostic value of two different single-sampling biomarker strategies for the instant rule-out of AMI.

Methods

From the Biomarkers in Acute Cardiac Care (BACC) cohort, we recruited consecutive patients with acute chest pain and suspected AMI presenting to the Emergency Department of the University Medical Center Hamburg-Eppendorf, Hamburg, Germany. We compared safety, effectiveness and 12-month incidence of the composite endpoint of all-cause death and myocardial infarction between (i) a single-sampling, dual-marker pathway combining high-sensitivity cardiac troponin I (hs-cTnI) and ultra-sensitive copeptin (us-Cop) at presentation (hs-cTnI ≤ 27 ng/L, us-Cop < 10 pmol/L and low-risk ECG) and (ii) a single-sampling pathway based on one-off hs-cTnI determination at presentation (hs-cTnI < 5 ng/L and low-risk ECG). As a comparator, we used the European Society of Cardiology (ESC) 0/1-h dual-sampling algorithm.

Results

We enrolled 1,136 patients (male gender 65%) with median age of 64 years (interquartile range, 51–75). Overall, 228 (20%) patients received a final diagnosis of AMI. The two single-sampling instant rule-out pathways yielded similar negative predictive value (NPV): 97.4% (95%CI: 95.4–98.7) and 98.7% (95%CI: 96.9–99.6) for dual-marker and single hs-cTnI algorithms, respectively (P = 0.11). Both strategies were comparably safe as the ESC 0/1-h dual-sampling algorithm and this was consistent across subgroups of early-comers, low-intermediate risk (GRACE-score < 140) and renal dysfunction. Despite a numerically higher rate of false-negative results, the dual-marker strategy ruled-out a slightly but significantly higher percentage of patients compared with single hs-cTnI determination (37.4% versus 32.9%; P < 0.001). There were no significant between-group differences in 12-month composite outcome.

Conclusions

Instant rule-out pathways based on one-off determination of hs-cTnI alone or in combination with us-Cop are comparably safe as the ESC 0/1 h algorithm for the instant rule-out of AMI, yielding similar prognostic information. Instant rule-out strategies are safe alternatives to the ESC 0/1 h algorithm and allow the rapid and effective triage of suspected AMI in patients with low-risk ECG. However, adding copeptin to hs-cTn does not improve the safety of instant rule-out compared with the single rule-out hs-cTn at very low cut-off concentrations.

Copeptin as a Diagnostic and Prognostic Biomarker in Cardiovascular Diseases

Copeptin is the carboxyl-terminus of the arginine vasopressin (AVP) precursor peptide. The main physiological functions of AVP are fluid and osmotic balance, cardiovascular homeostasis, and regulation of endocrine stress response. Copeptin, which is released in an equimolar mode with AVP from the neurohypophysis, has emerged as a stable and simple-to-measure surrogate marker of AVP and has displayed enormous potential in clinical practice. Cardiovascular disease (CVD) is currently recognized as a primary threat to the health of the population worldwide, and thus, rapid and effective approaches to identify individuals that are at high risk of, or have already developed CVD are required. Copeptin is a diagnostic and prognostic biomarker in CVD, including the rapid rule-out of acute myocardial infarction (AMI), mortality prediction in heart failure (HF), and stroke. This review summarizes and discusses the value of copeptin in the diagnosis, discrimination, and prognosis of CVD (AMI, HF, and stroke), as well as the caveats and prospects for the application of this potential biomarker.

Copeptin in fluid disorders and stress

Copeptin, a glycosylated peptide of 39 amino acids, is the C-terminal segment of arginine vasopressin (AVP) precursor peptide, which is consisted of two other fragments, vasopressin and neurophysin Ⅱ. The main physiological functions of AVP are fluid and osmotic balance, cardiovascular homeostasis and regulation of the endocrine stress response. Numerous studies have demonstrated that the endogenous AVP in plasma is a meaningful biomarker to guide diagnosis and therapy of diseases associated with fluids disorders and stress. However, due to its instability, short half-time life in circulation and lack of readily available AVP assays, clinical measurement of AVP is restricted. In contrast to AVP, copeptin which is released in an equimolar mode with AVP from the pituitary, has emerged as a stable and simple-to-measure surrogate marker of AVP and displays excellent potential in diagnosis, differentiation and prognosis of various diseases. This review will discuss the studies on the clinical value of copeptin in different diseases, especially in AVP-dependent fluids disorders, as well as issues and prospects of the application of this potential biomarker.

Biomarkers-in-Cardiology 8 RE-VISITED-Consistent Safety of Early Discharge with a Dual Marker Strategy Combining a Normal hs-cTnT with a Normal Copeptin in Low-to-Intermediate Risk Patients with Suspected Acute Coronary Syndrome-A Secondary Analysis of the Randomized Biomarkers-in-Cardiology 8 Trial

Regarding the management of suspected Non-ST-segment-elevation acute coronary syndrome (ACS), the main Biomarker-in-Cardiology (BIC)-8 randomized controlled trial study had reported non-inferiority for the incidence of major adverse cardiac events at 30 days in the Copeptin group (dual marker strategy of copeptin and hs-cTnT at presentation) compared to the standard process (serial hs-cTnT testing). However, in 349 (38.7%) of the 902 patients, high-sensitivity cardiac troponin was not available for the treating physicians. High sensitivity cardiac troponin T was re-measured from thawed blood samples collected at baseline. This cohort qualified for a re-analysis of the 30-day incidence rate of MACE (death, survived cardiac death, acute myocardial infarction, re-hospitalization for acute coronary syndrome, acute unplanned percutaneous coronary intervention, coronary bypass grafting, or documented life-threatening arrhythmias), or components of the primary endpoint including death or death/MI. After re-measurement of troponin and exclusion of 9 patients with insufficient blood sample volume, 893 patients qualified for re-analysis. A total of 57 cases were detected with high sensitivity cardiac troponin T ≥ 14 ng/L who had been classified as “troponin negative” based on a conventional cardiac troponin T or I < 99th percentile upper limit of normal. Major adverse cardiac events rates after exclusion were non-inferior in the Copeptin group compared to the standard group (4.34% (95% confidence intervals 2.60–6.78%) vs. 4.27% (2.55–6.66%)). Rates were 53% lower in the per-protocol analysis (HR 0.47, 95% CI: 0.18–1.15, p = 0.09). No deaths occurred within 30 days in the discharged low risk patients of the Copeptin group. Copeptin combined with high sensitivity cardiac troponin is useful for risk stratification and allows early discharge of low-to-intermediate risk patients with suspected acute coronary syndrome is as safe as a re-testing strategy at 3 h or later.

Advances in point-of-care testing for cardiovascular diseases

Point-of-care testing (POCT) is a specific format of diagnostic testing that is conducted without accompanying infrastructure or sophisticated instrumentation. Traditionally, such rapid sample-to-answer assays provide inferior analytical performances to their laboratory counterparts when measuring cardiac biomarkers. Hence, their potentially broad applicability is somewhat bound by their inability to detect clinically relevant concentrations of cardiac troponin (cTn) in the early stages of myocardial injury. However, the continuous refinement of biorecognition elements, the optimization of detection techniques, and the fabrication of tailored fluid handling systems to manage the sensing process has stimulated the production of commercial assays that can support accelerated diagnostic pathways. This review will present the latest commercial POC assays and examine their impact on clinical decision-making. The individual elements that constitute POC assays will be explored, with an emphasis on aspects that contribute to economically feasible and highly sensitive assays. Furthermore, the prospect of POCT imparting a greater influence on early interventions for medium to high-risk individuals and the potential to re-shape the paradigm of cardiovascular risk assessments will be discussed.

Critical appraisal of the 2020 ESC guideline recommendations on diagnosis and risk assessment in patients with suspected non-ST-segment elevation acute coronary syndrome

Multiple new recommendations have been introduced in the 2020 ESC guidelines for the management of acute coronary syndromes with a focus on diagnosis, prognosis, and management of patients presenting without persistent ST-segment elevation. Most recommendations are supported by high-quality scientific evidence. The guidelines provide solutions to overcome obstacles presumed to complicate a convenient interpretation of troponin results such as age-, or sex-specific cutoffs, and to give practical advice to overcome delays of laboratory reporting. However, in some areas, scientific support is less well documented or even missing, and other areas are covered rather by expert opinion or subjective recommendations. We aim to provide a critical appraisal on several recommendations, mainly related to the diagnostic and prognostic assessment, highlighting the discrepancies between Guideline recommendations and the existing scientific evidence.

Could Serum Copeptin Level Be an Indicator of Coronary Artery Disease Severity in Patients with Unstable Angina?

This study aimed to identify the serum copeptin levels in patients diagnosed with unstable angina (UA) and evaluate the relationship between the patients' copeptin levels and angiographic severity.A total of 200 patients who were diagnosed with UA and underwent coronary angiography were included in the study. Clinical, electrocardiographic, echocardiographic, and laboratory data (high-sensitivity cardiac troponin T and copeptin levels) as well as The Global Registry of Acute Coronary Events (GRACE) 1.0 risk score were recorded upon admission. Moreover, the Synergy Between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery (SYNTAX) score was calculated following coronary angiography.We isolated and defined two subgroups within our study population: group 1 included patients with non-significant coronary artery disease (CAD) (< 50% diameter stenosis, n = 105); group 2 included patients with significant CAD (≥ 50% diameter stenosis, n = 95). The number of cases with a GRACE score higher than 140 was significantly higher in group 2 than in group 1 (P < 0.001). The SYNTAX scores and copeptin levels were significantly higher in group 2 than in group 1 (P < 0.001 for both). A positive correlation was observed between the copeptin levels and SYNTAX scores (r = 0.683; P < 0.001), and the cut-off level of copeptin was 18.3 pmol/L (sensitivity of 74.7%, specificity of 83.8%, and area under the curve of 0.795).This study suggests that it may be beneficial to use conventional scoring systems and serum copeptin levels when identifying high-risk UA patients.

Investigation of the plasma copeptin level in cases with childhood migraine

Copeptin is a hypothalamic stress hormone that is synthesized in the hypothalamus together with Arginine-vasopressin and circulated from the neurohypophysis in equimolar amounts and can indicate the individual stress level. The aim of this study was to investigate the plasma copeptin level for childhood migraine headache. In this study, total oxidant status (TOS); total antioxidant status (TAS); oxidative stress index (OSI); and copeptin were measured in the plasma samples of 61 migraine patients and 60 matched healthy participants. The median plasma copeptin levels in the patients group and control group were 298.25 and 194.35 pg/mL, respectively. Copeptin levels were significantly higher in migraine patients than in the healthy control group. The specificity and sensitivity of copeptin for 249.5 pg/dL cut off value predicting diagnosis of migraine were 67% and 64%, respectively. In addition, TOS and OSI levels were found to be higher and TAS levels were significantly lower in patients with migraine than healthy controls. Plasma copeptin levels are thought to increase in cases of childhood migraine secondary to increased oxidative stress. In the diagnosis of childhood migraine cases, it can be used together with oxidative stress biomarkers such as TAS, TOS and OSI as a complementary parameter.

Copeptin as a marker of outcome after cardiac arrest: a sub-study of the TTM trial

Background

Arginine vasopressin has complex actions in critically ill patients, involving vasoregulatory status, plasma volume, and cortisol levels. Copeptin, a surrogate marker for arginine vasopressin, has shown promising prognostic features in small observational studies and is used clinically for early rule out of acute coronary syndrome. The objective of this study was to explore the association between early measurements of copeptin, circulatory status, and short-term survival after out-of-hospital cardiac arrest.

Methods

Serial blood samples were collected at 24, 48, and 72 h as part of the target temperature management at 33 °C versus 36 °C after cardiac arrest trial, an international multicenter randomized trial where unconscious survivors after out-of-hospital cardiac arrest were allocated to an intervention of 33 or 36 °C for 24 h. Primary outcome was 30-day survival with secondary endpoints circulatory cause of death and cardiovascular deterioration composite; in addition, we examined the correlation with extended the cardiovascular sequential organ failure assessment (eCvSOFA) score.

Results

Six hundred ninety patients were included in the analyses, of whom 203 (30.3%) developed cardiovascular deterioration within 24 h, and 273 (39.6%) died within 30 days. Copeptin measured at 24 h was found to be independently associated with 30-day survival, hazard ratio 1.17 [1.06–1.28], p = 0.001; circulatory cause of death, odds ratio 1.03 [1.01–1.04], p = 0.001; and cardiovascular deterioration composite, odds ratio of 1.05 [1.02–1.08], p < 0.001. Copeptin at 24 h was correlated with eCvSOFA score with rho 0.19 [0.12–0.27], p < 0.001.

Conclusion

Copeptin is an independent marker of severity of the post cardiac arrest syndrome, partially related to circulatory failure.

Trial registration

Clinical Trials, NCT01020916. Registered November 26, 2009.

Is high-sensitivity troponin, alone or in combination with copeptin, sensitive enough for ruling out NSTEMI in very early presenters at admission? A post hoc analysis performed in emergency departments

OBJECTIVES

Copeptin and high-sensitivity cardiac troponin (HS-cTn) assays improve the early detection of non-ST-segment elevation myocardial infarction (NSTEMI). Their sensitivities may, however, be reduced in very early presenters.

SETTING

We performed a post hoc analysis of three prospective studies that included patients who presented to the emergency department for chest pain onset (CPO) of less than 6 hours.

PARTICIPANTS

449 patients were included, in whom 12% had NSTEMI. CPO occurred <2 hours from ED presentation in 160, between 2 and 4 hours in 143 and >4 hours in 146 patients. The prevalence of NSTEMI was similar in all groups (9%, 13% and 12%, respectively, p=0.281).

MEASURES

Diagnostic performances of HS-cTn and copeptin at presentation were examined according to CPO. The discharge diagnosis was adjudicated by two experts, including cardiac troponin I (cTnI). HS-cTn and copeptin were blindly measured.

RESULTS

Diagnostic accuracies of cTnI, cTnI +copeptin and HS-cardiac troponin T (HS-cTnT) (but not HS-cTnT +copeptin) lower through CPO categories. For patients with CPO <2 hours, the choice of a threshold value of 14 ng/L for HS-cTnT resulted in three false negative (Sensitivity 80%(95% CI 51% to 95%); specificity 85% (95% CI 78% to 90%); 79% of correctly ruled out patients) and that of 5 ng/L in two false negative (sensitivity 87% (95% CI 59% to 98%); specificity 58% (95% CI 50% to 66%); 52% of correctly ruled out patients). The addition of copeptin to HS-cTnT induced a decrease of misclassified patients to 1 in patients with CPO <2 hours (sensitivity 93% (95% CI 66% to 100%); specificity 41% (95% CI 33% to 50%)).

CONCLUSION

A single measurement of HS-cTn, alone or in combination with copeptin at admission, seems not safe enough for ruling out NSTEMI in very early presenters (with CPO <2 hours).

TRIAL REGISTRATION NUMBER

DC-2009-1052.

Comparison of fourteen rule-out strategies for acute myocardial infarction

BACKGROUND

The clinical availability of high-sensitivity cardiac troponin (hs-cTn) has enabled the development of several innovative strategies for the rapid rule-out of acute myocardial infarction (AMI). Due to the lack of direct comparisons, selection of the best strategy for clinical practice is challenging.

METHODS

In a prospective international multicenter diagnostic study enrolling 3696 patients presenting with suspected AMI to the emergency department, we compared the safety and efficacy of 14 different hs-cTn-based strategies: hs-cTn concentrations below the limit of detection (LoD), dual-marker combining hs-cTn with copeptin, ESC 0 h/1 h-algorithm, 0 h/2 h-algorithm, 2 h-ADP-algorithm, NICE-algorithm, and ESC 0 h/3 h-algorithm, each using either hs-cTnT or hs-cTnI. The final diagnosis of AMI was adjudicated by two independent cardiologists using all available clinical information including cardiac imaging and serial hs-cTn concentrations.

RESULTS

AMI was the final diagnosis in 16% of patients. Using hs-cTnT, safety quantified by the negative predictive value (NPV) and sensitivity was very high (99.8-100% and 99.5-100%) and comparable for all strategies, except the dual-marker approach (NPV 98.7%, sensitivity 96.7%). Similarly, using hs-cTnI, safety quantified by the NPV and sensitivity was very high (99.7-100% and 98.9-100%) and comparable for all strategies, except the dual-marker approach (NPV 96.9%, sensitivity 90.4%) and the NICE-algorithm (NPV 99.1%, sensitivity 94.7%). Efficacy, quantified by the percentage of patients eligible for rule-out, differed markedly, and was lowest for LoD-algorithm (15.7-26.8%).

CONCLUSION

All rapid rule-out algorithms, except the dual-marker strategy and the NICE-algorithm using hs-cTnI, favorably combine safety and efficacy, and can be considered for routine clinical practice.

CLINICAL TRIAL REGISTRATION

NCT00470587, http://clinicaltrials.gov/show/NCT00470587.

Combined testing of copeptin and high-sensitivity cardiac troponin T at presentation in comparison to other algorithms for rapid rule-out of acute myocardial infarction

BACKGROUND

We aimed to directly compare the diagnostic and prognostic performance of a dual maker strategy (DMS) with combined testing of copeptin and high-sensitivity (hs) cardiac troponin T (cTnT) at time of presentation with other algorithms for rapid rule-out of acute myocardial infarction (AMI).

METHODS

922 patients presenting to the emergency department with suspected AMI and available baseline copeptin measurements qualified for the present TRAPID-AMI substudy. Diagnostic measures using the DMS (copeptin <10, <14 or < 20 pmol/L and hs-cTnT≤14 ng/L), the 1 h-algorithm (hs-cTnT<12 ng/L and change <3 ng/L at 1 h), as well as the hs-cTnT limit-of-blank (LoB, <3 ng/L) and -detection (LoD, <5 ng/L) were compared. Outcomes were assessed as combined end-points of death and myocardial re-infarction.

RESULTS

True-negative rule-out using the DMS could be achieved in 50.9%-62.3% of all patients compared to 35.0%, 45.3% and 64.5% using LoB, LoD or the 1 h-algorithm, respectively. The DMS showed NPVs of 98.1%-98.3% compared to 99.2% for the 1 h-algorithm, 99.4% for the LoB and 99.3% for the LoD. Sensitivities were 93.5%-94.8%, as well as 96.8%, 98.7% and 98.1%, respectively. Addition of clinical low-risk criteria such as a HEART-score ≤ 3 to the DMS resulted in NPVs and sensitivities of 100% with a true-negative rule-out to 33.8%-41.6%. Rates of the combined end-point of death/MI within 30 days ranged between 0.2% and 0.3% for all fast-rule-out protocols.

CONCLUSION

Depending on the applied copeptin cut-off and addition of clinical low-risk criteria, the DMS might be an alternative to the hs-cTn-only-based algorithms for rapid AMI rule-out with comparable diagnostic measures and outcomes.

Copeptin as a prognostic biomarker in acute myocardial infarction

BACKGROUND

Copeptin - the C-terminal section of vasopressin precursor - is a novel biomarker, that has been shown to be a useful prognostic factor in heart failure, ischemic stroke and in acute myocardial infarction (MI) but with restricted population and follow-up in ST-segment elevation MI (STEMI) setting. We evaluated in this study the hypothesis that copeptin measured on admission is an independent predictor of one-year all-cause mortality after a STEMI.

METHODS

Copeptin was measured immediately on arrival in the catheterization laboratory in a cohort of unselected STEMI patients and was compared to the peak of cardiac troponin I as a prognosis marker. One-year follow-up was performed.

RESULTS

We included 401 STEMI patients (77% of men, mean age 64 ± 14 years) treated by primary percutaneous coronary intervention. Copeptin on admission was significantly higher in patients who died during the one-year follow-up than in survivors (154.8 pmol/L; IQR [63.9-304.8] vs 30.3 pmol/L; IQR [10.8-93.5]); p < 0.0001). There was an increase in mortality at one year from the lowest to the highest quartile of copeptin. After Cox regression analysis, copeptin was an independent predictor of death at one year (adjHR 3.1, 95% CI [1.5-6.2], p = 0.001). When compared to the peak value of cardiac troponin I, copeptin measured on admission had a better prognostic value to predict one-year mortality (AUC of 0.74 vs 0.60, p = 0.022).

CONCLUSION

Copeptin measured on admission is a reliable and independent prognostic biomarker of one-year mortality in acute myocardial infarction patients.

Diagnostic accuracy of adding copeptin to cardiac troponin for non-ST-elevation myocardial infarction: A systematic review and meta-analysis

INTRODUCTION

This study aimed to determine the diagnostic accuracy of adding copeptin to cardiac troponin (cTn) on admission to the emergency department (ED) for non-ST elevation myocardial infarction (NSTEMI) compared to cTn alone.

MATERIALS AND METHODS

A literature search of MEDLINE, EMBASE, and the Cochrane Library was performed (search date: April 13, 2018). Primary studies were included if they accurately reported on patients with symptoms suggestive of acute myocardial infarction and measured both cTn alone and cTn with copeptin upon admission to the ED. The patients with evidence of ST elevation myocardial infarction were excluded. To assess the risk of bias for the included studies, the QUADAS-2 tool was used.

RESULTS

The study participants included a total of 7,998 patients from 14 observational studies. The addition of copeptin to cTn significantly improved the sensitivity (0.81 [0.74 to 0.87] vs. 0.92 [0.89 to 0.95], respectively, p <0.001) and negative predictive value (0.96 [0.95 to 0.98] vs. 0.98 [0.96 to 0.99], respectively, p <0.001) at the expense of lower specificity (0.88 [0.80 to 0.97] vs. 0.57 [0.49 to 0.65], respectively, p <0.001) compared to cTn alone. Furthermore, adding copeptin to cTn showed significantly lower diagnostic accuracy for NSTEMI compared to cTn alone (0.91[0.90 to 0.92] vs. 0.85 [0.83 to 0.86], respectively, p < 0.001).

CONCLUSIONS

Adding copeptin to cTn improved the sensitivity and negative predictive value for the diagnosis of NSTEMI compared to cTn alone. Thus, adding copeptin to cTn might help to screen NSTEMI early upon admission to the ED.

Initial Phase NT-proBNP, but Not Copeptin and High-Sensitivity Cardiac Troponin-T Yielded Diagnostic and Prognostic Information in Addition to Clinical Assessment of Out-of-Hospital Cardiac Arrest Patients With Documented Ventricular Fibrillation

AIM

Sudden cardiac arrest (SCA) secondary to ventricular fibrillation (VF) may be due to different cardiac conditions. We investigated whether copeptin, hs-cTnT and NT-proBNP in addition to clinical assessment may help to identify the etiology of SCA and yield prognostic information.

METHODS AND RESULTS

EDTA-blood was collected prior to or at hospital admission from patients with SCA of assumed cardiac origin. Clinical data were obtained from hospital records. VF was the primary heart rhythm in 77 patients who initially were divided into 2 groups based on whether they had an ischemic or non-ischemic mechanism as the most likely cause of SCA. They were further divided into 4 groups according to whether or not they had a history of previous heart disease. The patients were categorized by baseline clinical information, ECG, echocardiography and coronary angiography; Group 1 (n = 43): SCA with first AMI, Group 2 (n = 10): SCA with AMI and previous MI, Group 3 (n = 3): SCA without AMI and without former heart disease, Group 4 (n = 18): SCA without AMI and with known heart disease. Copeptin and hs-cTNT did not differ between patient groups, whereas NT-proBNP was significantly higher in patients with established heart disease without AMI and differed between non-AMI and AMI. Furthermore, NT-proBNP was significantly elevated in non-survivors as compared to survivors.

CONCLUSION

NT-proBNP provided both diagnostic and prognostic information in blood samples collected close to out-of-hospital resuscitation of VF patients, whereas copeptin and hs-cTnT failed to do so.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT02886273.

Novel Biomarkers to Detect Target Organ Damage in Acute Hypertension

PURPOSE OF REVIEW

Early lowering of blood pressure is advised for patients with severe hypertension associated with signs of impending or progressive organ damage, whereas aggressive treatment is not recommended in patients with asymptomatic severe hypertension. As treatment goals for asymptomatic hypertension and true hypertensive emergency drastically differ, it is essential to identify patients with evidence of impending or progressive organ damage. Biomarkers may assist providers in identifying high-risk patients who would benefit from early blood pressure reduction.

RECENT FINDINGS

In this review, we discuss both currently available and investigational biomarkers that may help identify patients who might benefit from more aggressive therapy. We focus on serum and urinary biomarkers associated with acute cardiovascular, renal, and cerebrovascular damage. There is a dearth of literature regarding the use of biomarkers to assess acute hypertension-related target organ damage. We are primarily forced to draw conclusions on the use of biomarkers from studies of related conditions such as acute heart failure. Further research is needed on the clinical significance of abnormal levels of novel biomarkers of renal, cardiac, and cerebral dysfunction in the setting of severe hypertension, particularly in those patients without overt clinical signs of organ failure.

Direct Comparison of 2 Rule-Out Strategies for Acute Myocardial Infarction: 2-h Accelerated Diagnostic Protocol vs 2-h Algorithm

BACKGROUND

We compared 2 high-sensitivity cardiac troponin (hs-cTn)-based 2-h strategies in patients presenting with suspected acute myocardial infarction (AMI) to the emergency department (ED): the 2-h accelerated diagnostic protocol (2h-ADP) combining hs-cTn, electrocardiogram, and a risk score, and the 2-h algorithm exclusively based on hs-cTn concentrations and their absolute changes.

METHODS

Analyses were performed in 2 independent diagnostic cohorts [European Advantageous Predictors of Acute Coronary Syndrome Evaluation (APACE) study, Australian–New Zealand 2-h Accelerated Diagnostic Protocol to Assess patients with chest Pain symptoms using contemporary Troponins as the only biomarker (ADAPT) study] employing hs-cTnT (Elecsys) and hs-cTnI (Architect). The final diagnosis was adjudicated by 2 independent cardiologists.

RESULTS

AMI was the final diagnosis in 16.5% (95% CI, 14.6%–18.6%) of the 1372 patients in APACE, and 12.6% (95% CI, 10.7%–14.7%) of 1153 patients in ADAPT. The negative predictive value (NPV) and sensitivity for AMI were very high and comparable with both strategies using either hs-cTnT or hs-cTnI in both cohorts (all statistical comparisons nonsignificant). The percentage of patients triaged toward rule-out was significantly lower with the 2h-ADP (36%–43%) vs the 2-h algorithm (55%–68%) with both assays and in both cohorts (P &lt; 0.001). The sensitivity of the 2h-ADP was higher for 30-day major adverse cardiovascular events.

CONCLUSIONS

Both algorithms provided very high and comparable safety as quantified by the NPV and sensitivity for AMI and major adverse cardiac events (MACE) at 30 days in patients triaged toward rule-out, although sensitivity for MACE at 30 days was lower with both algorithms in cohort 2. Although the 2-h algorithm was more efficacious, not all patients ruled out for AMI by this algorithm were appropriate candidates for early discharge. The 2h-ADP seems superior in the selection of patients for early discharge from the ED.

CLINICAL TRIAL REGISTRATION

APACE: http://clinicaltrials.gov/show/NCT00470587

ADAPT: Australia-New Zealand Clinical Trials Registry ACTRN12611001069943

Use of copeptin for rapid rule-out of acute myocardial infarction

Copeptin is currently understood as a quantitative marker of endogenous stress. It rises rapidly in multiple acute disorders including acute myocardial infarction. As a single variable, it has only modest diagnostic accuracy for acute myocardial infarction. However, the use of copeptin within a dual-marker strategy together with conventional cardiac troponin increases the diagnostic accuracy and particularly the negative predictive value of cardiac troponin alone for acute myocardial infarction. The rapid rule-out of acute myocardial infarction is the only application in acute cardiac care mature enough to merit consideration for routine clinical care. However, the dual-marker approach seems to provide only very small incremental value when used in combination with sensitive or high-sensitivity cardiac troponin assays. This review aims to update and educate regarding the potential and the procedural details, as well as the caveats and challenges of using copeptin in clinical practice.

Early Rule-Out and Rule-In Strategies for Myocardial Infarction

BACKGROUND

Patients with chest pain comprise a large proportion of emergency presentations and place a major burden on healthcare resources. Therefore, efforts to safely and rapidly identify those with and without acute myocardial infarction (AMI) are needed. The challenge for clinicians is to accurately identify patients with acute coronary syndromes, while balancing the need to safely and rapidly reassure and discharge those without serious conditions.

CONTENT

This review summarizes the evidence to date on optimum accelerated strategies for the rule-in and rule-out of AMI, using strategies focused on optimum use of troponin results. Evidence based on both sensitive and highly sensitive troponin assay results is presented. The use of novel biomarkers is also addressed and the combination of biomarkers with other clinical information in accelerated diagnostic strategies is discussed.

SUMMARY

The majority of patients, who are not at risk of myocardial infarction or other serious harm, may be suitable for discharge directly from the emergency setting using approaches focused on troponin algorithms and accelerated diagnostic protocols. Evidence about the clinical and health economic impact of use of such strategies is needed, as they may have major benefits for both patients and healthcare providers.

State-of-the-Art Evaluation of Emergency Department Patients Presenting With Potential Acute Coronary Syndromes

It is well established that clinicians cannot use clinical judgment alone to determine whether an individual patient who presents to the emergency department has an acute coronary syndrome. The history and physical examination do not distinguish sufficiently between the many conditions that can cause acute chest pain syndromes. Cardiac risk factors do not have sufficient discriminatory ability in symptomatic patients presenting to the emergency department. Most patients with non-ST-segment-elevation myocardial infarction do not present with electrocardiographic evidence of active ischemia. The improvement in cardiac troponin assays, especially in conjunction with well-validated clinical decision algorithms, now enables the clinician to rapidly exclude myocardial infarction. In patients in whom unstable angina remains a concern or there is a desire to evaluate for underlying coronary artery disease, coronary computed tomography angiography can be used in the emergency department. Once a process that took ≥24 hours, computed tomography angiography now can rapidly exclude myocardial infarction and coronary artery disease in patients in the emergency department.

Incremental value of copeptin in suspected acute myocardial infarction very early after symptom onset

BACKGROUND

Patients presenting very early after chest pain onset may provide a diagnostic challenge even when using a high-sensitivity cardiac troponin (hs-cTnT). We hypothesized that in these patients the incremental value of copeptin in the early diagnosis of acute myocardial infarction (AMI) may be substantial.

METHODS

We aimed to investigate the incremental value of copeptin in a pre-specified subgroup analysis of patients presenting with suspected AMI to the emergency department within 2 hours of symptom onset in a multicenter study. Copeptin was measured in a blinded fashion. Two independent cardiologists adjudicated the final diagnosis using all available clinical informations, including high-sensitivity cardiac troponin T (hs-cTnT).

RESULTS

Overall, 2000 patients were enrolled, of whom 519 (26%) arrived within 2 hours of symptom onset. Of these, 102 patients (20%) had an AMI. The additional use of copeptin did not increase diagnostic accuracy as quantified by the area under the receiver-operating characteristic curve (AUC) of hs-cTnT (0.87 (95% confidence interval (CI): 0.83-0.90) for hs-cTnT alone to 0.86 (95% CI: 0.82-0.90) for the combination; p = NS). Copeptin (using 9 pmol/L as a cut-off) increased the negative predictive value (NPV) of hs-cTnT (using 14 ng/L as a cut-off) alone from 93% (95% CI: 90-95%) to 96% (95% CI: 93-98%). The NPV for the combination of hs-cTnT and copeptin was lower in patients arriving in the first 2 hours than in those arriving after 2 hours: 96% (95% CI: 93-98%) versus 99% (95% CI: 99-100%), respectively.

CONCLUSIONS

The additional use of copeptin on top of hs-cTnT seems to lead to a small increase in NPV, but no increase in AUC. Routine use of copeptin in early presenters does not seem warranted.

One-hour rule-in and rule-out of acute myocardial infarction using high-sensitivity cardiac troponin I

We aimed to prospectively derive and validate a novel 0-/1-hour algorithm using high-sensitivity cardiac troponin I (hs-cTnI) for the early "rule-out" and "rule-in" of acute myocardial infarction (AMI).

METHODS

In a prospective multicenter diagnostic study, we enrolled 1,500 patients presenting with suspected AMI to the emergency department. The final diagnosis was centrally adjudicated by 2 independent cardiologists blinded to hs-cTnI concentrations. The hs-cTnI (Siemens Vista) 0-/1-hour algorithm incorporated measurements performed at baseline and absolute changes within 1 hour, was derived in the first 750 patients (derivation cohort), and then validated in the second 750 (validation cohort).

RESULTS

Overall, AMI was the final diagnosis in 16% of patients. Applying the hs-cTnI 0-/1-hour algorithm developed in the derivation cohort to the validation cohort, 57% of patients could be classified as "rule-out"; 10%, as "rule-in"; and 33%, as "observe." In the validation cohort, the sensitivity and the negative predictive value for AMI in the "rule-out" zone were 100% (95% CI 96%-100%) and 100% (95% CI 99%-100%), respectively. The specificity and the positive predictive value (PPV) for AMI in the "rule-in" zone were 96% (95% CI 94%-97%) and 70% (95% CI 60%-79%), respectively. Negative predictive value and positive predictive value of the 0-/1-hour algorithm were higher compared to the standard of care combining hs-cTnI with the electrocardiogram (both P < .001).

CONCLUSION

The hs-cTnI 0-/1-hour algorithm performs very well for early rule-out as well as rule-in of AMI. The clinical implications are that used in conjunction with all other clinical information, the 0-/1-hour algorithm will be a safe and effective approach to substantially reduce time to diagnosis.

Copeptin: Pathophysiology and potential clinical impact

Copeptin, a C-terminal part of the precursor pre-provasopressin is a novel biomarker of arginine-vasopressin (AVP) system. Measurements of AVP concentration are not used in clinical practice because of technical difficulties. Copeptin is synthesized in stoichiometric ratio with AVP, hence it reflects vasopressin concentration in human plasma and serum. This review outlines current research concerning the role of copeptin as a prognostic marker in different diseases and its potential clinical value.